This invention relates to portable electronic activation devices such as a remote control, and in particular to a portable electronic activation device having a receiver unit that remains unactivated until a transmitter unit is separated from the receiver unit, at which time the receiver unit is activated to a standby mode to receive signals from the transmitter unit.
In the typical control of an electronic device by a remote transmitter, the electronic device includes a receiver which is energized continuously in order to be able to receive signals from the transmitter. Most such transmitters are battery powered, since the transmitter is activated for only a short period of time, while the receivers are powered by line-current or a large, high capacity battery, since they must be continuously activated. Examples include remote locking/unlocking devices for vehicles, remote controls for televisions and electronic equipment, remote-activated burglar alarms, and the like. In all such devices, the receiver is normally not portable, either because it is connected to line current or includes such a large battery that portability is not readily feasible.
In the past, it has been impossible to provide a remote control for a portable device, because of the lack of capacity of the battery for the portable device. If the receiver of the portable device is activated continuously, even for the most efficient receiver unit, stored energy in the battery is quickly exhausted, and the remote control becomes useless until the battery is either replaced or recharged. If the receiver includes a switch to turn it on, battery power can be conserved, but a signal from the transmitter unit cannot be received until the receiver unit is switched on. Thus, the portable unit has limited utility, either because it is not activated continuously, or because, once activated, it has only a very limited battery life.
The present invention overcomes the drawbacks of the prior art by providing an electronic activation device having a receiver unit which is always activated only when receipts of signals from a transmitter unit is desired. The receiver unit includes a receiver, a power source for the receiver, and a control for electrically connecting the power source to the receiver for activating the receiver. The transmitter unit includes a transmitter for sending signals to the receiver. The receiver unit also includes a transmitter unit housing which is shaped to accommodate at least a portion of the transmitter unit, with the control being actuated by the transmitte unit when in the housing to prevent connection of the power source to the receiver.
In accordance with the preferred form of the invention, the housing comprises a receptacle in the receiver unit, and the transmitter unit is shaped to fit within the receptacle. In the form of the invention depicted, the receptacle is cylindrical, and the transmitter unit is generally cylindrical, as well.
In the preferred form of the invention, the control includes a normally closed contact, and means is provided in the receiver unit to open the contact when the transmitter unit is located in the receptacle. Preferably, the means to open the contact comprises a switch arm extending into the receptacle and being connected to the contact, with the switch arm being displacable by the transmitter unit when the transmitter unit is located in the receptacle.
Preferably, the receiver unit is a modular unit which can be connected to another device to activate that device. In this form of the invention, means is provided for activating the attached device, that means comprising a plug which is engagable with a receptacle in the attached device. In this manner, the electronic activation device according to the invention can be used, or not, by simply plugging it into another device and then using the remote control feature of the electronic activation device.
In accordance with the invention, the transmitter unit, in addition to its transmitter, also includes a power source and a switch for electrically connecting the power source to the transmitter to activate the transmitter for sending signals to the receiver. The switch is a normally open switch, and includes a push button for closing the switch to activate the transmitter. The power source comprises a battery with enough stored energy to power the transmitter to send activation signals over a desired distance to the receiver.